This research targets to present a case study on the annual comparative assessment of photovoltaic thermal collectors (PV/T) by using water and Ag/water nanofluid for five different cities in Pakistan. The assessment is conducted at monthly, daily, and hourly resolutions. PV/T collector is imitated through a set of energy balance based physical models which are solved numerically for two working fluids (i.e. water and Ag/water nanofluid) in a yearly simulation format (with hourly, daily, and monthly predictions) for five major cities of Pakistan (Taxila, Peshawar, Multan, Lahore, and Karachi). Detailed comparative assessment is carried out based on the performance indicators such as electrical efficiency, thermal efficiency, heat gain, and net electricity power generation. In the results section, hourly, daily, and monthly patterns of performance indicators using water and Ag/water nanofluid are reported, followed by a comparative study between the different cities having different climatic conditions. The sensitivity of nanofluid's mass flow rate and its particle concentration on the performance indicators is also reported, and the analysis of the sensitivity of the nanofluid characteristics on the pumping and the net useful power is also presented. Assessment has indicated that the overall efficiency for Taxila, Peshawar, Multan, Lahore, and Karachi cities are similar and around 66% despite having different latitude and longitudinal locations. While using silver nanofluid as a working fluid, compared to the usage of pure water as a working fluid, overall lesser efficiency is seen at around 63.80%, for selected cities.

中文翻译：

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全年纳米流体作用下光伏集热器每小时对比评估：以巴基斯坦主要城市为例

本研究旨在为巴基斯坦五个不同城市提供关于使用水和银/水纳米流体对光伏集热器 (PV/T) 进行年度比较评估的案例研究。评估以每月、每天和每小时的分辨率进行。PV/T 集热器通过一组基于能量平衡的物理模型进行模拟，这些模型以年度模拟格式（每小时、每天和每月预测）对五个主要的两种工作流体（即水和 Ag/水纳米流体）进行数值求解巴基斯坦城市（塔西拉、白沙瓦、木尔坦、拉合尔和卡拉奇）。根据电效率、热效率、得热量、净发电量等性能指标进行详细对比评估。在结果部分，每小时，每天，报告了使用水和 Ag/水纳米流体的性能指标的月度模式，然后在具有不同气候条件的不同城市之间进行了比较研究。还报道了纳米流体的质量流量及其颗粒浓度对性能指标的敏感性，并分析了纳米流体特性对泵送和净有用功率的敏感性。评估表明，塔克西拉、白沙瓦、木尔坦、拉合尔和卡拉奇城市的整体效率相似，约为 66%，尽管纬度和经度位置不同。在使用银纳米流体作为工作流体时，与使用纯水作为工作流体相比，在选定的城市中，总体效率较低，约为 63.80%。